Dis- and tris-azo dyestuffs and process of making same



Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE 1115- AND' TRIS-AZO DYESTUFFS AND PROC- ESS OF MAKING SAME No Drawing. Application March 24, 1936, Serial No. 70,610. In Germany April 9, 1935 16 claims.

v The present invention relates to disand tris azo dyestuifs and a process of making same.

We have found that very valuableazo dyestuffs are obtained by coupling the tetrazo'compound of 4,4-diaminodiphenylamine or its sulfonic acids in an alkaline medium with one molecular proportion of a 1-hydroXy-S-aminonaphthaIene sulfonic acid capable'of being coupled and one molecular proportion of a hydroxy compound of the benzene series which is capable of being coupled at least once.

As 1 -hydroxy-8-aminonaphthalene sulfonic acids may be mentioned both monosulfonic and polysulfonic acids, as for example 1-hydroxy-8- aminonaphthalene-3,6-, 4,6-, or 2,4-disulfonic acid, 1-hydroxy-8-aminonaphthalene-4- or 5- sulfonic acid. As hydroxy compounds or the benzene series capable of being coupled at least once may be mentioned for example hydroxybenzene, ,hydroxymethyland hydroxydimethyl benzenes, 1,3-dihydroxybenzene and its derivatives, 1,2,3-trihydroxybenzene, ortho-hydroxy benzoic acid, hydroxymethyl-benzene carboxylic acids, meta-hydroxydiphenylamine and also derivatives thereof which are still capable of being coupled in the phenol ring, such as 2',4- dinitro 3 -'hydroxydiphenylamine, 5'-hydroxy- 2,4-dinitro-3-hydroxydiphenylamine or 2',4',6- trinltro-3-hydroxydiphenylamine. If the disazo dyestuffs obtained are capable of being coupled they may .be converted into trisazo dyestuffs by treatment with diazotized aromatic amines.

The dyestuffs obtainable in the said manner are, generally speaking, deep blue to blue-black; they are especially suitable for dyeing leather. They are distinguished by a good stability to acids and alkalies and good solubility and they penetrate so deeply into the leather that they are also suitable for dyeing velour leather. The dyestuffs also have an aflinity for cotton and viscose artificial silk.

The following examples will further illustrate how our s'aid invention may be carried out in practice, but the invention is not restricted to these examples. The parts are by weight.

Example 1 After salting out, a dyestufi is obtained which yields dark blue to black shades of good fastness to polishing on chrome calf velour leather. The dyestuff has a good stability to acids and alkalies and may also be used for dyeing cotton.

Dyestuffs having similar good properties are obtained by employing 1-hydroxy-2-methy1benzene or 1,3-dihydroxybenzene instead of l-hydroxyl-methylbenzene. If 4,4diam-inodiphenylamine-Z-sulfonic acid be employed insteadoi" 4,4'-diaminodiphenylamine, dyestuffs are obtained which, generally speaking, yield a somewhat more red dyeing and have a somewhatslighter dyeing power for cotton.

Example 2 19.9 parts of 4,4-diaminodiphenylamine are tetrazotized and coupled with 31.9 parts of l-hydroxy-8aminonaphthalene-2,4-disulfonic acid in alkaline solution. To the resulting diazo compound of the monoazo dyestufi there is then added a weakly alkaline solution of 11.9 parts of 1,-3-dihydroxybenzene and the mixture is stirred until the formation of the disazo dyestuff is completed. The dyestuff dyes leather and cotton beautiful blue shades. The dyestufi obtained by means of 1-hydroxy-3-methoxybenzene is similar.

Example 3 27.9 parts of 4,4-diaminodiphenylamine-Z-sulfonic acid are tetrazotized and the tetrazo compound is coupled in alkaline solution With 31 .9 parts of 1-hydroxy-8-aminonaphthalene-3,6-disulfonic acid. There are then added to the slightly alkaline solution 12 parts of 1,3-dihydroxybenzene, a dyestuif thus being obtained which dyes leather black shades.

Instead of 1,3-dihydroxybenzene, a trihydroxybenzene, as for example 1,2,3-trihydroxybenzene or 1,3,5-trihydroxybenzene, may be employed. Equally good dyestufis are thus obtained. In order to displace the shades of the dyestufis somewhat more towards green, they may be aftertreated for example with the diazo compound of 13.8 parts of 1-amino-4-nitrobenzene so that a tr'isazo dyestufi is obtained which dyes markedly greener shades.

Example 4 19.9 parts of 4,4-diaminodiphenylamine are tetrazotized and coupled in a solution rendered alkaline with sodium carbonate with 31.9 parts of 1-hydroxy-8-aminonaphthalene-3,6-disulfonic acid. When the l-hydroxy-8-aminonaphthalene-3,6-disulfonic acid has been used up, 18.5

whole then being stirred for several hours. When coupling is completed, the product is salted out and filtered off by suction. A blue dyestufi is obtained which yields deep dark blue to black shades of good fastness to polishing on chrome calf velour leather.

ing 1-hydroXy-8-aminonaphthalene 2A- or 4,6- disulfonic acid instead of l-hydroxy-8-ai'ninonaphthalene-3,6disulfonic acid, If the first coupling component is a l-hydroxy-B-aminonaphthalene monosulfonic acid, the presence of at least one further sulfom'c group in the second.

coupling component or in the tetr azo compound is desirable in order to ensure a satisfactory solubility of the dyestuif.

Example 5 27.2 parts of 4,4diaminodiphenylamine-2-" 3-hydroxydiphenylamine dissolved in dilute caus tic soda solution are introduced, the whole then being stirred for several hours. When coupling is completed, the product is salted .out and filtered off by suction. A dyestufi is thus obtained which dyes chrome tanned velour leather blueblack shades of good fastness to polishing.

If 5hyd roxy-2, ldinitro-3-hydroxydiphenylamine or 2',4,6-trinitro-3-hydroxydiphenylamine be employed instead of 2, l'-dinitro-3- hydroxydiphenylamine dyestuffs having similar properties are obtained.

What we claim is: 1

1. A process for the production of azo dyestuffs which consists in coupling a tetrazotized 4,4'-diaminodiphenylamine with one molecular proportion of a 1-hydroxy-8-aminonaphthalene sulfonic acid capable of being coupled and one molecular proportion of a hydroxy benzene capable of being coupled at least once.

2. A process for the production of azo dyestuffs which consists in coupling a tetrazotized 4,4- diaminodiphenylamine with one molecular proportion of a l-hydroxy-S-aminonaphthalene disulfonic acid capable of being coupled and one molecular proportion of a hydroxy benzene capable of being coupled at least once.

3. A process for the production of azo dyestufis which consists in coupling a tetrazotized 4,4- diaminodiphenylamine with one molecular proportion of 1-hydroxy-8-aminonaphthalene-3,6- disulfonic acid capable of being coupled and one molecular proportion of a hydroxy benzene capable of being coupled at least once.

Dyestuffs having similar p p ti s a tai d for xa m y employ; which consists in coupling a tetrazotized 4,4-

When the 4. A process for the production of .azo dyestuffs which consists in coupling a tetrazotized 4,4- diaminodiphenylamine with one molecular proportion of 1-hydroxy-8-aminonaphthalene 3,6- disulfonic acid capable of being coupled and one molecular proportion of a hydroxymethylbenzene capable of being coupled at leastonce;

5. A process for the production of azo dyestuffs diaminodiphenylamine with one molecular proportion of l-hydroxy-8-aminonaphthalene-3,6-

' disulfonic acid capable of being coupled and one molecular proportion of 1-hydroXy-4-methylbenzene.

. 6. A process forthe production of azo dyestuffs which consists in coupling a tetrazotized 4,4-

diaminodiphenylaminewith one molecular proportion of l-hydroxy-8-aminonaphthalene-3,6- disulfonic acid capable of being coupled and one molecular proportion of 1,3-dihydroxybenzene.

7. A proces's for the production of azo dyestuffs whichcon sists in coupling a tetrazotized4,4"-

diaminodiphenylamine with one molecular proportion of l-hydroxy-B-aniinonaphthalene-3,6-

Vdisulfonic acid capableof being coupled and one molecular proportion of a meta-hydroxydiphenyl amine capable of being coupled at least once.

8. A process for the production of azo dyestuffs which consists in coupling a tetrazotized 4,4-

7 diaminodiphenylamine with one molecular proportion: of 1-hydroxyr8-aminonaphthalene-3,6- disulfonic acid capable of being coupled and one molecular proportion of 'meta-hydroxydiphenylamine. Y V 9. A20 dyestuffs correspondingto the general formula f i wherein R stands for the radicle of a l-hydroxy- B-aminonaphthalen sulfonic acid capable of being coupled, R1 for a radicle of the group consisting of diphenylamine and its sulfonic acids the benzene nuclei of which are combined with the nitrogen'atom; in the para-positions to the azo groups and Rz for the radicle of a hydroxy benzene capable of being coupled at least once.

10. Azo dyestufis of the general formula wherein R stands iorthe radicle of a l-hydroxy- NH: OH

V, V f 65 wherein R2 stands for the radicle of a hydroxy benzene capable of being coupled at least once.

I 12. A20 dyestuffs of the general formula.

wherein R2 stands for the radicle of a hydroxy- 15. The azo dyestufi of the formula methylbenzene.

NH2 OH H HOaS s 03H 16. The azo dyestuff of the formula,

N H OH Hogs s 05H H0 13. The azo dyestuff of the formula NH; OH OH 1105s s 03H on, 14. A dyestuffs of the general formula,

N112 OH 7 HOzS s 03H Q wherein R2 stands for the radicle of a meta- HANS KRZIKALLA.

hydroxydiphenylamine.

LUDWIG NEUMANN. 

